Post-marketing surveillance of the safety and effectiveness of nivolumab for classic Hodgkin lymphoma in Japan.

Nivolumab was approved for relapsed/refractory classic Hodgkin lymphoma (cHL) in Japan in 2016. After its approval, a prospective, non-interventional, observational post-marketing surveillance was initiated to evaluate the safety and effectiveness of nivolumab treatment for up to 12 months in patients with relapsed/refractory cHL. Of 304 registered patients, 288 were included in safety analyses and 282 in effectiveness analyses. There were 191 (66.3%) male patients, median age was 64.0 years, and 54 patients (18.8%) had performance status ≥ 2. Treatment-related adverse events (TRAEs) were reported in 183 (63.5%) patients, with grade 3-5 TRAEs in 86 (29.9%). The most common TRAEs were infusion reaction (14.6%), hepatic function abnormal (5.9%), interstitial lung disease (ILD) (5.6%), and hypothyroidism (5.2%). TRAEs of special interest in ≥ 5% of patients were infusion reaction (15.6%), hepatic failure/hepatic dysfunction/hepatitis/cholangitis sclerosing (13.2%), thyroid dysfunction (9.7%), and ILD (7.3%). In multivariable analyses, prior allogeneic hematopoietic stem cell transplantation was a risk factor for hepatic failure/hepatic dysfunction/hepatitis/cholangitis sclerosing, and prior thyroid gland disorders was a risk factor for thyroid dysfunction. The overall response rate was 61.7%. In conclusion, nivolumab showed a similar safety profile and comparable effectiveness to that reported in clinical trials for relapsed/refractory cHL (CheckMate 205, ONO-4538-15).

Synthesis and evaluation of a potent, well-balanced EP2/EP3 dual agonist.

A highly potent and well-balanced dual agonist for the EP2 and EP3 receptors is described. Optimization of the lead compound was accomplished in consideration of the relative agonist activity against each EP subtype receptor and the pharmacokinetic profile. As the result, 2-[(2-{(1R,2R)-2-[(1E,4S)-5-cyclopentyl-4-hydroxy-4-methyl-1-penten-1-yl]-5-oxocyclopentyl}eth-yl)thio]-1,3-thiazole-4-carboxylic acid (10) showed excellent potency (human EC50 EP2 = 1.1 nM, EP3 = 1.0 nM) with acceptable selectivity over the EP1 and EP4 subtypes (>2000-fold). Further fine-tuning of compound 10 led to identification of ONO-8055 as a clinical candidate. ONO-8055 was effective at an extremely low dose (0.01 mg/kg, po, bid) in rats, and dose-dependently improved voiding dysfunction in a monkey model of underactive bladder (UAB). ONO-8055 is expected to be a novel and highly promising drug for UAB.

Discovery of highly potent dual EP(2) and EP(3) agonists with subtype selectivity.

The cyclic carbamate derivatives, 2-{[2-((4S)-4-{(1E,3R)-8-fluoro-3-hydroxy-4,4-dimethyl-1-octenyl}-2-oxo-1,3-oxazolidin-3-yl)ethyl]sulfanyl}-1,3-thiazole-4-carboxylic acid (5) and 2-{[2-((4S)-4-{(1E,3R)-3-[1-(4-fluorobutyl)cyclobutyl]-3-hydroxy-1-propenyl}-2-oxo-1,3-oxazolidin-3-yl)ethyl]sulfanyl}-1,3-thiazole-4-carboxylic acid (7) were identified as the first potent dual EP2 and EP3 agonists with selectivity against the EP1 and EP4 subtypes. Compounds 5 and 7 demonstrated highly potent dual EP2 and EP3 agonist activity with EC50 values of 10nM or less. In addition, these compounds possess structural features distinct from natural prostaglandins, such as a cyclic carbamate moiety, a dimethyl or cyclobutyl group and a terminal fluorine atom.

Discovery of novel S1P2 antagonists, part 3: Improving the oral bioavailability of a series of 1,3-bis(aryloxy)benzene derivatives.

The structure of the S1P2 antagonist 1 has been modified with the aim of improving its oral bioavailability. The chemical modification of the alkyl chain and carboxylic acid moieties of 1 led to significant improvements in the oral exposure of compounds belonging to this series. The optimization of the ring size of the urea portion of these molecules also led to remarkable improvements in the oral exposure. Based on these changes, the pyrrolidine derivative 16 was identified as a suitable candidate compound and showed excellent pharmacokinetic profiles in rat and dog, while maintaining high levels of potency and selective antagonistic activity toward S1P2.

Discovery of novel S1P2 antagonists. Part 2: Improving the profile of a series of 1,3-bis(aryloxy)benzene derivatives.

Our initial lead compound 2 was modified to improve its metabolic stability. The resulting compound 5 showed excellent metabolic stability in rat and human liver microsomes. We subsequently designed and synthesized a hybrid compound of 5 and the 1,3-bis(aryloxy) benzene derivative 1, which was previously reported by our group to be an S1P2 antagonist. This hybridization reaction gave compound 9, which showed improved S1P2 antagonist activity and good metabolic stability. The subsequent introduction of a carboxylic acid moiety into 9 resulted in 14, which showed potent antagonist activity towards S1P2 with a much smaller species difference between human S1P2 and rat S1P2. Compound 14 also showed good metabolic stability and an improved safety profile compared with compound 9.

Discovery of novel S1P2 antagonists. Part 1: discovery of 1,3-bis(aryloxy)benzene derivatives.

The structure-activity relationships of a novel series of sphingosine-1-phosphate receptor antagonists have been examined in detail. The initial hit compound 1 was modified through synthesis to improve its S1P2 activity. The synthesis of a series of analogs revealed that 1,3-bis(aryloxy)benzene derivatives, as represented by 22, are potent and selective S1P2 antagonists.